Automatic steering mechanism.



K. DOUGAN.

AUTOMATIC STEERING MECHANISM.

APPLICATION FILED APR-18 I910.

PatentedSept. 21, 1915.

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K. DOUGAN.

AUTOMATIC STEERING MECHANISM.

APPLICATION EILED APR. 18. 1910.

Patented Sept. 21, 1915.

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KENNEDY DOUGAN, 0F MINNEAPOLIS, MINNESOTA.

AUTOMATIC STEERING MECHANISM.

Application filed April 18, 1910.

- of relieving or taking the place of the steersman in case of sickness or disability. In power launches, having sometimes a sole occupant, it will steer the boat in any desired direction while the person is engaged in other duties. The action of the steering mechanism is to hold the boat, ship or torpedo in a straight course regardless of the action of winds, tides or currents.

For a clear understanding of the invention, reference is to be had to the accompanying drawings in which,

Figure 1 is a top plan of a mechanism embodying my invention, omitting only the motor and the rudder. Fig. 2 is a vertical section viewed on line 2 of Fig. 1. Fig. 3 is a vertical section viewed on line 3 of Fig. 1, also indicating the motor. Fig. 4 may be considered a part of Fig. 1, and shows the connecting rod connected with a rudder to actuate the same. Fig. 5 is an end elevation of the sliding frame shown in section in Fig. 3. Fig. 6 is a vertical section disclosing the drive shaft and. parts directly mounted thereon. Fig. 7 is a detail elevation of the large stoppawl.

One mechanical expression of the inventive idea is found in the drawings, and as here illustrated,it comprises: (a) a motor to supply sufficient power to operate the rudder through the medium of (b) a primary motion-translating mechanism comprising normally idle gears; (c) a controlling element for said mechanism; (a?) a secondary motion translating mechanism adapted to actuate and control said controlling element; (6) a magnet needle (compass); and (f) means controlled mechanically by said needle for starting said secondary mechanism and determining the direction in which the rudder will be turned. Said primary Specification of Letters Patent.

Patented Sept. 21, 1915.

Serial No. 556,171.

and secondary mechanisms are identical in mechanical principle, and may be identical in construction. In practice, however, I prefer to construct them differently as herein shown and described. In Fig. 1 the primary (larger) mechanism is shown at theleft, and the secondary (smaller) mechanism at the right. The secondary mechanism will be first described on account of its simpler construction as shown. Said mechanism comprlses, in part, a rotary element 1, upon which is concentrically fixed the compass box 4. Element 1 is shown as a mutilated gear which has gear teeth 5 and is mounted on a shaft 6. Secured to and moved by this gear 1 is an arm 7 that controls the direction of operation of the primary rudder mechanism. Mounted on a fixed base 8 is the frame 9 of the mechanism aboutto be described. Said frame has bearings 10 for a drive shaft 12, on which are bevel or worm gears 13 and 13', also a gear 14, driven by a pinion 15 and pulle 16. Journaled in the frame 9 is a rotary siiaft 17, disposed radially with respect to the center of the compass box 4. Fixed on the shaft 17 1s a bevel gear 18 meshing with 13, and a yoke 19 that carries a shaft 20 on which are fixed two planet gears 21, 21 of unequal diameters. double gear 2223, one of which meshes with the teeth 5 of wheel 1, the other with planet gear 21. Also rotatable on shaft 17, is a sleeve or hub 24 having on its outerend a ratchet wheel 25 and on its inner end a gear 26, meshing with the other planet gear 21. Note that the gears 26 and 21' are equal in size, while gears 23 and 21 are unequal. In the opposite end of the frame this construction is duplicated, and I have desig nated corresponding parts by similar numerals. The other shaft 17', however, is rotated in the opposite direction from shaft 17', and the teeth of the two ratchets 25, 25 are oppositely directed. Their end elevation would appear as shown at the left of Fig. 1 where a similar but larger mechanism 59, 59. is shown The magnetic needle 27 is fixed upon a shaft or spindle 28, the lower end of which is pivoted in a jewel in a cup 4, which contains a liquid. Secured on the shaft 28 is a float 29 and a' number of vanes 30. The float bears up on the staff and reduces friction atthe bearing pivot. The vanes in the Rotatably on shaft 17 is a lbs liquid damp the oscillations of the needle.

- to the face or web of the large gear 1. This ring, hereinafter termed the clutch-ring, and the co -engaging clutch member 33, are clearly shown in section in Fig. 2. The clutch-ring is formed with a T-head, or double flange. The clutch member, 33, which is rigidly secured to the pawl 32, is C-shaped in section and loosely straddles the ring 35 as shown, being normally out of contact therewith. Its inturned edges are adapted to engage, frictionally, the lower faces of the head of the clutch-ring. The pawl 32 is of such length that it may stand between the ratchets 25, 25 without touching either of them. This position will ocour only, of course, when the compass needle is pointing toward the magnetic north and south and at rest.

The base 8 on which the entire mechanism is mounted is fixed immovably on a shelf or table in the boat or torpedo, so that when the parts are in the relative position just noted, any deviation of the boat or torpedos course will cause the stop-pawl 32 to engage one of the ratchets. But it is, of course, necessary to provide for adjusting the angle between the compass needle and the pawlbar 31. This is readily effected by mounting the needle frictionally and rotatably on the staff, 28. The angles are read from a vernier 36 that is held by the bar 31, as shown.

The arm 7 carried by the large gear 1 passes freely under the frame 9, which is constructed to permit a range of'movement of said arm of about 30 degrees, or as much more as may be found desirable.

The operation of the mechanism that has been described is as follows: The straight line course of the boat or torpedo having been decided, the magnetic needle 27 is adjusted at such an angle by the vernier 36 that when the boat or torpedo is in longitudinal'alinement with such course the stoppawl 32 will stand clear of the ratchets 25, The shafts 12, 17 and 17 are driven continuously. The resistance, frictional and other, of the large gear 1 to being turned, holds the small bevel gears 22, 22" from rotating; therefore, the companion gears 23, 23' are stationary. The bodily revolution of the yokes 19, 19 carrying the planet gears 21, 21, etc., imparts a slow differential rotation of the gears 26, 26 and ratchets 25, 25'.

If either ratchet be now held against rotation, the bevel gear 22 or .22 on the same shaft will be forced to rotate, and will turn the large gear 1 and shift the arm 7. Supposing the compass 27 to have caused the stop-pawl 32 to engage the ratchet 25, the engaged end of the pawl is borne down by the ratchet and is tilted until the clutch member 33 becomes jammed upon the clutch-ring 35; by reason of this tilting action the bar 31 is slightly twisted and the opposite ends of said member 33 engage the respective upper and lower faces of the head of the clutch-ring. -VVhen the ratchet can turn no farther the gear 22 is forced to rotate, turning the large gear 1, arm 7 and clutch-ring 35. Said ring being clutched by the member 33, necessarily moves the latter with it, thereby disengaging the pawl from the ratchet. The pawl'and clutch member are now righted by the resilience of the pawl-bar, which is made resilient for that purpose; the clutch member 33 again hangs clear of the ring 35 and the compass needle is free to turn. If the deviating force persists, or continues, the pawl will immediately reengage the same ratchet, and the operation will be repeated, resulting in further movement of the arm 7. Said arm being movable in one direction by the operation of one set of gears, is movable in the reverse direction by the operation of the other set of gears, as will be obvious without description.

Though the part 35 is shown as a full annulus the only part thereof that co-acts with the clutch member 33 is a segment or are thereof, corresponding to the length of the gear 5. Hence, the member 35 may be in the form of a segment of an annulus.

It now remains to describe the primary translating mechanism, the function of which is to apply any desired degree of power to the rudder for shifting it. This mechanism is precisely the same in princr ple as the smaller one just described, but for 110 practical reasons a different structure is shown. Furthermore, I propose to show the one mechanism as a modification of the other. In the primary mechanism as shown, the frame on which the planet gearing is 115 journaled is mounted slidably, and corresponds in function to the large gear 1 of the other mechanism. The ratchet and pawl arrangement is modified by providing a clutch that holds the pawl stationary while the 120 ratchet wheel is moved away from it by the motion of the sliding frame. The mechanism comprises the slidable frame 38; a fixed frame composed of a base 39 and an upright plate 40; gearing mounted on or in I to said frame 38 at 42 is shown in Fig. 4 as ,connected directly to a tiller 43 on the post 44 of a'rudder 45, so that the rectilinear motion of said frame shall actuate the rudder. The frame 38 is provided with parallel flanges 46 that are held tightly though slidably in ways 47, 48, as clearly shown in Fig. 3. A large coeflicient of friction in these ways is desirable, and may be easily adjusted by means of gibs, not shown. For clearness .of illustration the upper way 47 is omitted in Fig. 1. The sides of frame 38 are rigidly connected by end pieces 49, indicated sectionally in Fig. 1. Referring now to Fig. 6, a rotary shaft 50 is journa'led partly in fixed bearings 51 and partly in bearings 52 held by the slidable frame 38. Said shaft is held from end movement by set-collars 53 and has fixed thereon two worms 54, 54, that are right and left-hand respectively. The driving pulley 55 is splined on the shaft and is held from end movement by the bearings 51 and collars 56. The frame 38 carries two sets of gears which are proportioned and arranged in the same manner as the gears of the secondary mechanism. The shafts 57, 57 carry worm-wheels 58, driven by the worms 54, 54 so the ratchets 59, 59 turn in opposite directions, and the rack bar 61 is moved in opposite directions by reason of the yoke e, and the gears a, b, c and d, which operate in the same manner as the corresponding parts of the secondary mechanism already described. The gears (Fig. 3) are always in mesh with a fixed rack-61, secured to the frame 40 by brackets 62. The double-acting stoppawl 63, is here supported loosely between parallel plates 64, having registering straight slots 65 therein. Said pawl is provided with lateral lugs 66, of suflicient size to-provide torsional strength; said lugs project into the respective slots 65 and are less thick than the slots are wide, in order to permit a tilting of the pawl and a clutching effect between the lugs and the walls of said slots. The controller-arm 7 (as it now may be termed) projects through a slot in wall 40 and has pivotedv thereto at 67 a horizontal .link or rod 68, pivotally connected with the middle of the pawl 63 upon a cross-pin 69 (Fig. 7). The length of the slot 65 equals, approximately, the length of the rack 61, which measures the travel of the frame 38. The operation of this mechanism is as follows: The drive shaft 50 is continuously rotated by a motor, as 70, to rotate the ratchets in the direction of the arrow, Fig. l. The friction existing between the slidable frame and its ways (which may be increased by any additional device) holds the rudder in the position to which it was last moved. Now, should the vessel deviate sufliciently to start the secondary mechanism which ineludes the arm 7, said arm will move the pawl 63 against one or the other of the ratchets 59, 59'. The effect will be that one of the gears 60 will roll upon the rack 61.

thereby forcing the frame 38 and rod 41 one way or the other and shifting the rudder. These movements follow every action of the secondary mechanism, and said actions continue until the compass needle will hold its pawl 32 half-way between the ratchets 25, the boat or torpedo being then in the true course. Each engagement of the primary pawl 63, results in the pawl being turned about its pivot, which obviously causes the lugs 66 to bind in the slots 65. So the pawl is thus held by the pressure of a ratchettooth while the same tooth is pulled off from the pawl by the rack and pinion motion. The pawl is capable of following the ratchets to any point within their range of movement.

A Very valuable characteristic of the operation of these mechanisms lies in the fact that the parts to be movedi. e. the pawl 32 first and finally the rudder-are moved by short steps only. The result is that they are never moved too far, because the pawls 32 and 63 are never permitted to hold the wheels long enough to permit any great movement of the arm 7 or of the rudder. But Where a large swing of the rudder 1s actually required, the mechanism acts with quick repeated impulses until that movement has been imparted.

Having thus described the invention, what I claim and desire to secure by Letters Patent is:

1. In a dirigible object, the combination with a rudder, of a primary rudder-actuating mechanism including continuously and oppositely rotated elements, a secondary mechanism controlling said rotated elements, said secondary mechanism including continuously and oppositely rotated elements, and a constant director controlling the rotated elements of the secondary mechanism.

2. In a dirigible object, a motion-translating mechanism having a step-by-step motion, a rudder actuated thereby, a mechanical controlling element for starting and directing said mechanism, a motion-translating mechanism having a step-by-step movement adapted to control said controlling element, a constant director, and means governed by said director for starting and directing the second said mechanism.

3. In, a mechanism of the character de scribed, the combination with a rudder, of a step by step moving rudder actuating mechanism, a step by step moving controlling mechanism for the rudder actuating mechanism, and amagnet needle controlling the latter mechanism. I

4. In a mechanism of the character described, the combination with a rudder, of a primary rudder actuating mechanism including continuously and oppositely rotative elements, a secondary mechanism controlling the oppositely rotative elements of the primary mechanism, the secondary mechanism including continuously and oppositely rotative elements, and a magnetic needle controlling the oppositely rotative elements of the secondary mechanism.

5. In a boat, torpedo, or other dirigible object, a motion-translating mechanism having a step-by-step movement, a rudder actuated thereby, a mechanical controlling element for starting and directing said mechanism, a motion-translating mechanism having a step-by-step movement adapted to control said controlling element, a magnetic needle, means for damping the oscillation of the needle, and means controlled by the needle for starting and-directing the second sai-d mechanism.

6. In a boat, torpedo, or other dirigible object; a motion-translating mechanism having normally idle and normally moving gears and adapted to transmit power, a motor, a rudder, a mechanical controller element adapted to start the idle gears of said mechanism, a smaller motion-translat ing mechanism adapted to actuate said controller element, said second motion translating mechanism comprising normally idle and normally moving gears; a magnet needle, means to damp the oscillation of the needle, and means mechanically controlled by the needle for starting the idle gears of the second said mechanism.

7. In a boat, torpedo, or other dirigible object, a motor, a power-transmitting mechanism operatively connected with said motor, a rudder, a controller element for starting said mechanism, a small powertransmitting mechanism for actuating initially said controller element, means for disengaging said controller element, a magnet needle, means to damp the oscillation of the needle, a second controller-element initially actuated by the needle for starting the second said mechanism, and means for automatically disengaging the second said controller element.

8. In a boat, torpedo, or other dirigible 9. In a boat, torpedo, or other dirigible object, a power transmitting and motiontranslating mechanism comprising pawland-ratchet controlled gearing, adapted to control and actuate the rudder, a magnet needle, means to damp the oscillation of the needle. means actuated by the needle for starting and determining the direction of movement of the rudder, and means controlled by the pawl mechanism and connected to the rudder, whereby the rudder is moved step by step by intermittent movements of the mechanism until the dirigible object is brought into the true course.

10. In a boat, torpedo, or other dirigible object, a pair of continuously power-driven ratchets, a pivoted bar adjacent thereto, a stop-pawl carried by said bar and playing between said ratchets, a clutch member carried by said pawl, a magnetic needle attached to said bar and directing the angular position of said bar, differential gears geared with said ratchets, a rotative gear and a clutch member actuated by said differentials, said last named clutch member being formed to co-act with the first named clutch member when said pawl is moved by one of said ratchets, and a reciprocative controller element actuated by said rotative gear.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

KENNEDY DOUGAN. Witnesses i N. O. THORI, M. A. SMITH. 

